Using tannins as active compounds to develop antioxidant and antimicrobial chitosan and cellulose based films

[EN] Three tannin extracts from different sources (white peel grape (W), red peel grape (R) and oak bark (O)) have been used to obtain active films based on different polysaccharides: chitosan (CH), methylcellulose (MC) and hydroxypropylmethylcellulose (HPMC). Tannin-rich films were obtained by casting as monolayers (by blending all the components) and as bilayers (one polysaccharide layer plus one tannin layer applied as a coating). Microstructural and physicochemical properties (water solubility, water vapor permeability, mechanical and optical properties), as well as the antioxidant and antimicrobial activities of the films, were analysed. Tannins, regardless of their origin, acted as crosslinking agents when incorporated into CH or MC films due to the establishment of specific associations, mainly hydrogen bonds and hydrophobic interactions. Thus, these tanninrich films turned less water soluble, mechanically stiffer and less stretchable. In contrast, tannins provoke precipitation in the HPMC film-forming solutions and the application of tannins onto the HPMC film surface gave rise to a weakened network due to the local precipitation of HPMC-tannin complexes. The greatest antioxidant capacity was found in both mono and bilayer tannin-rich MC based films in different food simulants, in line with a tannin release from the polymer matrix. The MC bilayer films also exhibited a bacteriostatic activity against both E.Coli and L. innocua. So, MC films with tannins could represent a good alternative as active coatings or packaging material so as to prevent the occurrence of oxidative reactions in sensitive food products or to control bacterial growth.The authors acknowledge the financial support from the Spanish Ministerio de Economía y Competitividad through the project PID2019-105207RB-ICano, A.; Contreras Monzón, CI.; Chiralt Boix, MA.; González Martínez, MC. (2021). Using tannins as active compounds to develop antioxidant and antimicrobial chitosan and cellulose based films. Carbohydrate Polymer Technologies and Applications. 2:1-9. https://doi.org/10.1016/j.carpta.2021.100156S19

Comportamiento de 13 modelos de cinta de riego en condiciones de invernadero con agua regenerada

El objetivo de este trabajo ha sido seleccionar modelos de cinta de riego con una mejor adaptación a las condiciones de invernadero y riego con aguas regeneradas. Se ha evaluado el comportamiento de 13 modelos comerciales de cintas de riego seleccionados de entre los más utilizados en los cultivos hortícolas al aire libre, y aquellos que, las empresas instaladoras y fabricantes consideren que, por sus características, pueden tener un buen comportamiento con este tipo de aguas. En la evaluación de campo todos los emisores han presentado valores de uniformidad elevados al comienzo de la campaña de riego. Cinco de las cintas se clasifican como excelentes y el resto como buenas. Al finalizar las 114 horas de trabajo decae sustancialmente la uniformidad. El comportamiento tras la finalización de la primera campaña de riego se puede considerar equiparable al obtenido en un estudio previo con una selección de 20 emisores en ramal convencional y este tipo de aguas. Se puede concluir que las cintas de riego localizado pueden ser una alternativa a los ramales de riego convencionales cuando se riega con aguas residuales urbanas regeneradas, siempre que se elija un material de una mínima calidad y el ratio de sustitución garantice una uniformidad alta

INFLUENCIA DE LA TEXTURA DEL SUELO EN LOS BULBOS HÚMEDOS DESARROLLADOS EN SUELO ENARENADO CON EMISORES DE RIEGO LOCALIZADO DE BAJO CAUDAL

[EN] We measured the moisture distribution in 20 soils under “arenado” system in the county Campo de Dalías (Almeria), drip irrigated and a pepper crop. Flow drippers 3l.h-1 were used with a density of 2 emiters.m-2 and a run time of 30 minutes. It has been found that there is great heterogeneity in the physical properties of soils despite being artificially supplied ones. The most important factor in explaining differences in moisture distribution was the soil texture. Trials it appears that there are problems in the distribution of irrigation due to the presence of impermeable layers. Moreover moisture levels found prior to suggest that the soils are being watered excessively and the wet area reaches almost the entire culture surface.[ES] Se ha medido la distribución de la humedad en 20 suelos, en sistema enarenado en la comarca Campo de Dalías (Almería), regados por goteo y bajo cultivo de pimiento. Se utilizaron goteros de caudal 3l.h-1 con una densidad de 2 emisores.m-2 y un tiempo de riego de 30 minutos. Se ha encontrado que existe una gran heterogeneidad en las propiedades físicas de los suelos a pesar de tratarse de suelos artificialmente aportados. El factor más importante para explicar las diferencias en la distribución de humedad fue la textura del suelo. De los ensayos se deduce que existen problemas en la distribución del riego debido a la presencia de horizontes impermeables. Por otra parte los niveles de humedad encontrados antes de los riegos sugieren que se está regando en exceso los suelos y que el área mojada alcanza a casi la totalidad de la superficie de cultivoZapata Sierra, A.; Contreras París, J.; Martín Usero, F.; Baeza Cano, R. (2015). INFLUENCIA DE LA TEXTURA DEL SUELO EN LOS BULBOS HÚMEDOS DESARROLLADOS EN SUELO ENARENADO CON EMISORES DE RIEGO LOCALIZADO DE BAJO CAUDAL. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1431OC

Mapping bridges between anxiety, depression, and somatic symptoms in primary care patients: a network perspective

In primary care centers, emotional disorders (EDs; depression, anxiety, and somatoform disorders) frequently appear to be associated. However, there is no previous information on the key (bridge) symptoms that maintain comorbidity. The current study aimed to identify symptoms that may play a linking role in bridging comorbidity among EDs from a network analysis perspective. A sample of adult primary care patients (N = 1704) with symptoms of EDs was assessed using the Patient Health Questionnaire (PHQ). Network analysis was applied to examine the network structure, communities, expected influence, and bridge symptoms between depressive, anxiety, and somatic symptoms. Sad mood and low energy were the most central symptoms. Furthermore, low energy, fainting spells, sad mood, and restlessness were detected as prominent bridge symptoms between anxiety, depression, and somatic symptoms. These bridge symptoms could be therapeutic targets for early intervention and prevent the development of comorbidity among EDs. The results of this research highlight the importance of symptom-specific functional properties for the activation of communities within EDs, providing new insights on a complex phenomenon such as comorbidity

Efficient inhibition of iron superoxide dismutase and of Trypanosoma cruzi growth by benzo[g]phthalazine derivatives functionalized with one or two imidazole rings

The synthesis and trypanosomatic behavior of a new series of 1,4-bis(alkylamino)benzo[g]phthalazines 1−4 containing the biologically significant imidazole ring are reported. In vitro antiparasitic activity against Trypanosoma cruzi epimastigotes is remarkable, especially for compound 2, whereas toxicity against Vero cells is very low. Conversion of epimastigotes to metacyclic forms in the presence of the tested compounds causes significant decreases in the amastigote and trypomastigote numbers. Fe-SOD inhibition is noteworthy, whereas effect on human Cu/Zn-SOD is negligible.The authors thank the Spanish CICYT for the financial support

1,4-Bis(alkylamino)benzo[g]phthalazines able to form dinuclear complexes of Cu(II) which as free ligands behave as SOD inhibitors and show efficient in vitro activity against Trypanosoma cruzi

The synthesis of a new series of 1,4-bis(alkylamino)benzo[g]phthalazines 1–3 is reported, and their ability to form dinuclear complexes with Cu(II) assayed. The geometry of the complexes is dependent on the nature of the electron-donor sites at the sidechains. Compounds 1 and 2, that contain sp3 or sp2 nitrogens at the end of the alkylamino groups, originate monopodal dinuclear complexes which seem to include endogenous OH bridges, and the sidechains seem to actively participate in complexation. However, the substitution of nitrogen by oxygen in 3 leads to a tripodal dinuclear complex in which the sidechains are not involved. The in vitro antiparasitic activity on Trypanosoma cruzi epimastigotes and amastigotes and the SOD activity inhibition have been evaluated for compounds 1–3, and, as expected, 1 and 2 show in all cases relevant results, whereas 3 is always the less active among the three substrates tested.The authors thank the Spanish Comision Interministerial de Ciencia y Tecnologia for the economical support given to this work (SAF99-0066)

In vivo trypanosomicidal activity of imidazole- or pyrazole-based benzo[ g ]phthalazine derivatives against acute and chronic phases of chagas disease

The in vivo trypanosomicidal activity of the imidazole-based benzo[g]phthalazine derivatives 1−4 and of the new related pyrazole-based compounds 5 and 6 has been studied in both the acute and chronic phases of Chagas disease. As a rule, compounds 1−6 were more active and less toxic than benznidazole in the two stages of the disease, and the monosubstituted derivatives 2, 4, and 6 were more effective than their disubstituted analogs. Feasible mechanisms of action of compounds 1−6 against the parasite have been explored by considering their inhibitory effect on the Fe-SOD enzyme, the nature of the excreted metabolites and the ultrastructural alterations produced. A complementary histopathological analysis has confirmed that the monosubstituted derivatives are less toxic than the reference drug, with the behavior of the imidazole-based compound 4 being especially noteworthy.The authors thank the Santander-Universidad Complutense Research Program (Grant GR58/08-921371-891), the Spanish MEC Project (Grant CGL2008-03687-E/BOS), and the MCINN Projects (CTQ2009-14288-C04-01 and Consolider CSD2010-00065) for financial support